The international legal system is a complex set of norms, customs, and legal regimes that regulate the interaction and mutual action of its components and bring them into a coherent framework. While we are faced with a general system of international law, it is possible for several subsystems to exist within this systematic framework. The present article seeks to answer the question of what is the position of international security regimes in the international legal system. The aim of the present study is also to explain the institutional position of international security regimes in the legal system governing the international legal system. In this research, using the institutionalist approach in the field of “International Law and International Relations” and through the systematic analysis of international law, the structure of the international legal system is defined and the types of interaction of players in this system are described. Based on this research, it is concluded that international institutions provide an opportunity for states that have not achieved the desired results in strategic interactions to improve their results by creating a new balance. In order for such a balance to be stable, the institution must create common expectations of behavior. Such expectations can only be supported and guaranteed through a theory of regimes that acts as a bridge between international law and international relations.